Pulley Apparatus for Resistance Exercises

ABSTRACT

The present invention is a pulley apparatus for resistance exercises comprising: a housing with an upper end, a lower end, an interior channel extending through the housing, and an exterior surface; a weight stack movable within the housing; and a pulley system comprising in the interior: at least two upper pulleys attached to the upper end of the housing, and at least one lower pulley attached to the weight stack; and on the exterior surface: at least two swivel pulleys attached to the upper end of the housing, and first and second outer pulleys, the first outer pulley located below the swivel pulleys and the second outer pulley located below the first outer pulley; and a pulley rope received by the upper pulleys, the lower pulleys, the swivel pulleys and the outer pulleys such that a first end of the pulley rope is secured to one of the outer pulleys and a second end of the pulley rope is received lastly by the other outer pulley, whereby force exerted on the second end of the pulley rope moves the weight stack. The pulley apparatus may also contain an upper and lower housing that may be disassembled and may be joined to form a combined housing.

FIELD OF THE INVENTION

The invention relates generally to a pulley apparatus for resistance exercises, and specifically to a pulley apparatus that may be used to warm up, practice a movement and improve physical movements including those in high velocity sports, such as hitting, swinging, throwing, kicking, as well as for use in physical rehabilitation.

BACKGROUND OF THE INVENTION

Resistance and weight training are used to improve and rehabilitate muscle strength. Resistance can be created using the individual's own weight or through ropes or bands with tension. Tension bands have been used in the field of sports rehabilitation and strengthening, particularly for shoulder injuries. Tension bands may be made of elastic, latex and rubber tubing of different lengths and sizes for different parts of the body, e.g. shoulder, wrist, legs. Home gym systems have been made using pulleys and resistance or weights for exercising all parts of the body.

Conventional exercise pulley machines typically have a large footprint from the dual guide rods set about six to ten inches apart with rectangular weights of eight to twelve inches long. The pulley systems of conventional exercise pulley apparatus also limit the range of motion of its users.

What is needed is a compact and adjustable pulley apparatus, which is capable of modulating the amount of resistance and that may be used for various body motions to simulate actual sports movement or as needed to rehabilitate an injury. What is also needed is a pulley apparatus that avoids the ballistic effects of a single axis pulley system and provides a wide arc of motion, resistance in a full circle, a superior means to test the range of motion of a particular body part, and provides injury rehabilitation motions.

SUMMARY OF THE INVENTION

This invention relates to a pulley apparatus for resistance exercises.

In a first embodiment of the invention there is a pulley apparatus for resistance exercises comprising:

-   -   a housing with an upper end, a lower end, an interior channel         extending through the housing, and an exterior surface,     -   a weight stack movable within the housing, and     -   a pulley system comprising in the interior         -   (a) at least two upper pulleys attached to the upper end of             the housing,         -   (b) at least one lower pulley attached to the weight stack,         -   and on the exterior surface         -   (c) at least two swivel pulleys attached to the upper end of             the housing,         -   (d) first and second outer pulleys, the first outer pulley             located below the swivel pulleys and the second outer pulley             located below the first outer pulley, and     -   a pulley rope received by the upper pulleys, the lower pulleys,         the swivel pulleys and the outer pulleys such that a first end         of the pulley rope is secured to one of the outer pulleys and a         second end of the pulley rope is received lastly by the other         outer pulley, whereby force exerted on the second end of the         pulley rope moves the weight stack.

In the first embodiment of this pulley apparatus the weight stack is comprised of individual weights and additionally includes a weight selection means to adjust the amount of resistance by increments of the individual weights.

In the first embodiment of this pulley apparatus there are additionally one or more weight alignment rods in the channel of the housing and holes in the individual weights, whereby the weight alignment rods pass through the holes in the individual weights.

In the first embodiment of this pulley apparatus there is additionally a top plate that is secured to the upper end of the housing and a bottom plate that is secured to the lower end of the housing, and the weight alignment rods are secured to the top plate and bottom plate.

In the first embodiment of this pulley apparatus there is additionally a guide rail on the exterior surface of the housing and outer pulley positioning devices, wherein the outer pulleys are affixed to the pulley positioning devices, and the pulley positioning devices are capable of being moved along the guide rail or fixed in position on the guide rail.

In a second embodiment of this invention there is a pulley apparatus for resistance exercises comprising:

-   -   an upper housing detachably connected to a lower housing that         forms a combined housing with an upper end, a lower end, an         interior channel extending through the combined housing, and an         exterior surface,     -   a weight stack movable within the housing, and     -   a pulley system comprising in the interior         -   (e) at least two upper pulleys attached to the upper end of             the housing,         -   (f) at least one lower pulley attached to the weight stack,         -   and on the exterior surface         -   (g) at least two swivel pulleys attached to the upper end of             the housing,         -   (h) first and second outer pulleys, the first outer pulley             located below the swivel pulleys and the second outer pulley             located below the first outer pulley, and     -   a pulley rope received by the upper pulleys, the lower pulleys,         the swivel pulleys and the outer pulleys such that a first end         of the pulley rope is secured to one of the outer pulleys and a         second end of the pulley rope is received lastly by the other         outer pulley, whereby force exerted on the second end of the         pulley rope moves the weight stack.

In the second embodiment of this pulley apparatus the weight stack is comprised of individual weights and additionally includes a weight selection means to adjust the amount of resistance by increments of the individual weights.

In the second embodiment of this pulley apparatus there are additionally grooves in the individual weights and one or more weight alignment rods in the upper housing and an equal number of weight alignment rods in the lower housing, whereby in the combined housing, the weight alignment rods are aligned and glide along the grooves in the individual weights.

In the second embodiment of this pulley apparatus the weight alignment rods in the upper housing are secured to the interior of the upper housing and the weight alignment rods of the lower housing are secured to the interior of the lower housing.

In the second embodiment of this pulley apparatus there is additionally a guide rail on the exterior surface of the lower housing and outer pulley positioning devices, wherein the outer pulleys are affixed to the pulley positioning devices, and the pulley positioning devices are capable of being moved along the guide rail or fixed in position on the guide rail.

The pulley apparatus of this invention may additionally include a base.

The pulley apparatus of this invention may additionally include mounting attachments on the housing whereby the pulley apparatus may be secured to a surface.

DESCRIPTION OF THE DRAWINGS

In the drawings which illustrate by way of example only, preferred embodiments of the invention:

FIG. 1 is a perspective view of a pulley apparatus according to a first embodiment of the present invention;

FIG. 2 is a perspective view of a pulley apparatus according to the first embodiment with a transparent housing to show the interior;

FIG. 3 is a perspective view of sections of the pulley apparatus according to the first embodiment with a transparent housing to show the interior;

FIG. 4 is a perspective view of the bottom of the pulley apparatus according to the first embodiment with a transparent housing to show the interior;

FIG. 5 is a perspective view of a pulley positioning device of a pulley apparatus;

FIG. 6 is a perspective view of sections of the pulley apparatus according to a second embodiment of the present invention;

FIG. 7 is a perspective view of sections of the pulley apparatus according to the second embodiment with a transparent housing to show the inner workings;

FIG. 8 is a perspective view of a pulley rope of a pulley apparatus according to the second embodiment with no housing;

FIG. 9 is a perspective view of sections of a pulley rope of the pulley apparatus according to the second embodiment with no housing;

FIG. 10 is a side view of a pulley apparatus according to the second embodiment showing the pulley rope set up with a handle with a transparent housing to show the inner workings;

FIG. 11 is a side view of a pulley apparatus according to the second embodiment showing the pulley rope set up with a handle with a transparent housing to show the inner workings;

FIG. 12 is a perspective view of sections of the pulley apparatus according to the second embodiment mounted to a base with a transparent housing to show the inner workings;

FIG. 13 is a perspective view of a pulley apparatus according to the second embodiment with attachments for mounting;

FIG. 14 is a perspective view of the bottom of a pulley apparatus according to the second embodiment in use with a transparent housing to show the inner workings;

FIG. 15 is a perspective view of a disassembled pulley apparatus according to the second embodiment with a transparent housing to show the inner workings.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, a pulley apparatus according to an embodiment of the invention is shown generally at 10 comprising a housing 15. The housing is in the shape of a tube and may be made of steel, aluminum or other materials. The housing has a top plate 40 attached to an upper end of the housing. The upper end of the housing is cut away to allow a pulley rope (not shown) to move through from the interior of the housing to the exterior. The pulley apparatus of FIG. 1 can be adapted to be mounted to a wall or provided with a base to be used on the ground which is shown in later figures.

Referring to FIG. 3, the top plate 40 protrudes to allow attachment of at least two swivel pulley brackets 50 each containing the same number of swivel pulley wheels 60. The lower end of each of the swivel pulley brackets 50 are attached to a swivel pulley bottom plate 70.

Referring to FIGS. 2 and 3, in which the housing is transparent to show the inner workings of the pulley apparatus, the housing 15 is adapted to hold a weight stack 80 comprising of a series of weight bars 90 stacked on top of one another. The weight bars 90 are held on a weight bearing shaft 400 (visible in FIGS. 7 and 14) that runs through the centre of the weight bars. The weight bearing shaft 400 is affixed to the top weight in the weight stack and is free at its bottom end. The weight bearing shaft contains holes through which the amount of weight stack to be lifted is adjusted through the use of an adjustment pin 100 that may be inserted in a hole in any individual weight. In this embodiment, the holes in the individual weights are found in a groove in each individual weight which lines up at opening 310. The adjustment pin 100 goes through one of the holes in the weight bearing shaft and accordingly all of the weights in the weight stack at and above the adjustment pin are lifted when the pulley is in use. The weight bearing shaft is lifted up through the interior of the housing along with the weights when the pulley is in use. Spacers 390 may be placed in between or affixed to the individual weight bars 90 to stop the weights from banging into one another.

Referring to FIG. 3, an embodiment of the pulley apparatus is further shown with a transparent housing 15 to allow the inner workings of the pulley apparatus, namely a pulley system, to be seen. An upper pulley U-bracket 220 containing three upper pulley wheels 230 is attached to the inside of the upper end of the housing 15 and is substantially perpendicular to the swivel pulley bracket 50.

Referring to FIGS. 3 and 4, in which the housing is also transparent to show the inner workings of the pulley apparatus, two or more weight alignment rods 255 run through the length of the housing. The weight alignment rods 255 are held in place by the bottom disc plate 420 attached to the lower end of the housing 15 and the top disc plate 410 attached to the upper end of the housing. The top disc plate has been machined in its centre to allow the movement of the ropes inside the plate. In one aspect of the present invention the bottom and top disc plates are aluminum. The weight alignment rods 255 may be threaded at the bottom end and held on the plate by hex nuts at the bottom of the plate. On the top plate the weight alignment rods 255 have threaded holes and may be held in place by a screw and a hex nut. The hex nuts at each end help create tension in the rods to minimize deflection. It should be understood that other methods may be used to secure the weight alignment rods to the bottom and top disc plates.

The weight bars 90 of the weight stack 80 have two or more holes for the insertion of the weight alignment rods. In one aspect of the present invention, there are nylon bushings (not shown) placed in each hole; one on top, and one at the bottom, to help minimize friction and improve alignment. The weight alignment rods are extended all the way to the top disc plate allowing for a wider range of motion.

A lower pulley U-bracket 290 with two lower pulley wheels 300 is attached to the uppermost weight bar 370. An adjustment pin 100 is used to choose the amount of weight bars selected and the weight bars 90 are held in at the lower end by the bottom plate 420. As shown in FIG. 3, an opening 310 may be provided in the housing so that the adjustment pin can be moved from one weight to another, as desired, through the housing. As in traditional pulley apparatus, by inserting the adjustment pin into a specific weight bar when the weight stack is at rest, the weight lifted by the user will be each of the weight bars above and including the weight bar in which the adjustment pin is placed.

Mounted on the housing 15 is guide rail 120. One or more pulley positioning devices 130 is slidably mounted on the guide rail 120.

Referring to FIG. 5, which shows the pulley positioning device in more detail, each pulley positioning device 130 contains a guide tube 140 that slides along the guide rail. Protruding from the surface of the guide tube 140 is a plunger barrel 150 with an internal supporting cup 160. The plunger barrel 150 is adapted to receive a threaded bolt 165 with a turning knob 170 into the supporting cup 160. In an embodiment of the present invention the plunger barrel 150 contains neoprene 180 at the end point of the plunger barrel 150, which is in contact with the guide rail 120. The threaded bolt 165 is of a length greater than the plunger barrel 150 and through rotation of the threaded knob 170, the guide tube 140 may be either secured to the guide rail 120 or loosened to move along the guide rail 120.

Mounted on the guide rail 120 by way of a bracket 190 is a pulley wheel bracket 200 containing an outer pulley wheel 210. The outer pulley wheel 210 of a first pulley positioning device is off-set to the plunger barrel 150. A second outer pulley wheel 210 of a second pulley position device is off-set to the plunger barrel 150 in a different direction than the first pulley positioning device, thus preventing tangling of the pulley rope 320.

By moving the guide tube along the guide rail via the rotation of the knob, the outer pulley wheel may be moved along the guide rail thereby accommodating different heights of its user's or positioning of the outer pulley wheel relative to the user's body part that will be pulling the weight, for example, the users' ankle, knee, or wrist.

It is understood that different mechanisms may be used to move the guide tube along the guide rail. For example, the plunger barrel may contain a coil spring, for example those plunger barrels 150 shown in FIGS. 6 to 10 and 12 to 15, and the guide rail may contain bores through which the plunger barrel may be moved between (not shown). However, the movement of the guide tube along the guide rail shown in the figures is advantageous as it permits infinite adjustment of the guide tube along the guide rail, thereby accommodating all users and uses of the pulley apparatus.

Referring to FIGS. 6 to 10 and 15, a pulley apparatus according to another embodiment of the present invention is shown generally at 10 comprising an upper housing 20 and lower housing 30. The difference from the earlier embodiment is that the upper housing 20 is detachable from the lower housing 30 and in this embodiment the weight alignment rods (260 and 270) are not continuous through the upper housing and lower housing. The pulley apparatus of FIGS. 6 to 10 and 15 can be adapted to be wall mountable (FIG. 13) or provided with a base to be used on the ground (FIG. 12).

Referring to FIG. 7 in which the upper housing 20 and lower housing 30 are transparent to allow the inner workings to be seen, a protuberance 240 is provided at the exterior surface of the upper end of the lower housing that connects the upper housing 20 to the lower housing 30 through a J-slot 250 at the lower end of the upper housing. In order to assemble the upper and lower housing, the protuberance 240 of the lower housing is aligned with the opening of the J-slot 250 on the upper housing. The protuberance is inserted into the J-slot and the lower housing is rotated so that the protuberance is in end of the J-slot.

Three upper weight alignment rods 260 are fixed in the upper housing and three lower weight alignment rods 270 are fixed in the lower housing. The upper and lower weight alignment rods are positioned so that when the upper and lower housings are connected to one another by way of the protuberance and J-slot, each of the three upper and lower weight alignment rods align with one another. It is understood that different manner of attaching the upper and lower housing may be used.

The weight bars 90 that form the weight stack 80 contain grooves 280 (FIG. 9) so that they may slide over the lower weight alignment rods 270, a close-up of which is seen in FIG. 14. A lower pulley U-bracket 290 with two lower pulley wheels 300 is attached to the uppermost weight bar 370. An adjustment pin 100 is used to choose the amount of weight bars selected and the weight bars 90 are held in at the lower end by the bottom plate 110. As shown in FIG. 14, an opening 310 is provided in the lower housing so that the adjustment pin can be moved from one weight to another, as desired, through the outer housing. As in traditional pulley systems, by inserting the adjustment pin into a specific weight bar when the weight stack is at rest, the weight lifted by the user will be each of the weight bars above and include the weight bar in which the adjustment pin is placed.

Referring to FIG. 15, showing the second embodiment of the present invention with a detachable upper and lower housing, a stow pin 380 may be inserted in a hole below the uppermost weight bar from one side of the housing to the other. The stow pin 380 acts to retain the weight stack in the lower housing 30 when the upper and lower housing are detached; for example, during shipment of the pulley system. When the stow pin 380 is in place, the upper housing and lower housing may be completely detached by moving the uppermost weight bar 370 and weight bearing shaft 400 into the upper housing 30, thereby moving the pulley rope 320 out of the lower housing and into the upper housing, and disengaging the protuberance 240 from the J-slot 250. Detaching the upper housing and lower housing makes the pulley system easy to transport and store.

Referring to FIGS. 8 and 9, a pulley system without the housing or guide rail is shown, demonstrating the movement of the pulley rope 320 through the pulley system, in particular the path of the pulley rope 320 around the pulleys of the pulley system. In an embodiment of the present invention, a single pulley rope is used. The pulley rope extends from one of the one or more outer pulley wheels 210, where the end of the pulley rope is secured, through one of the swivel pulley wheels 60 and then one of the upper pulley wheels 230. The pulley rope then extends from the upper housing into the lower housing through the first lower pulley wheel 300 and back up to the second upper pulley wheel 230. The pulley rope again extends down through the second lower pulley wheel 300 and back up through the third upper pulley wheel 230, and out of the upper housing and through the second swivel pulley wheel 60, through the second outer pulley and secured onto itself. Each end of the pulley rope may be secured to an outer pulley wheel 210 in any manner, for example a knot or a karabiner.

The ratio of three upper pulley wheels to two lower pulley wheels has the effect of lightening the amount of weight being lifted by the user so that the user of the pulley system does not lift, swing, kick, etc. the full weight that is being raised from the weight stack. The lifting of a smoothly liftable weight is desirable in a sport training setting as the user may still move quickly, for example, to swing the baseball bat or tennis racket that is attached to the handle, or may still quickly kick their foot that is attached to the pulley system by the strap.

The liftable weight load is also more desirable when the pulley system is being used in a physiotherapy setting or other therapeutic/rehabilitation setting as the injured party often starts recovery training with lower weights in order to build muscle strength for recovery or initial resistance training.

Referring to FIG. 10, a pulley apparatus is further shown with a pulley rope 320 extending through an outer pulley wheel ideal for hand or arm movements, for example, throwing. One end of the rope has a handle 340. The choice of weight provides more or less resistance to the throwing action.

In an aspect of the present invention the pulley apparatus shown in FIG. 10 may be used by a baseball player to improve their swing by attaching a baseball bat to the handle thereby allowing the player to practice their swing.

Referring to FIG. 11, a pulley apparatus is further shown with a pulley rope 320 extending through an outer pulley close to the bottom of the pulley system which is ideal for ankle or leg use, such as kicking. One end of the pulley rope 320 has a strap 340 for attachment to a body part, for example, the ankle.

The present invention may be transformed from the pulley apparatus of FIG. 10 in which the handle is attached to an end of the pulley rope attached to an upper pulley positioning device to the pulley apparatus of FIG. 11 in which the handle is attached to an end of the pulley rope attached to the lower pulley positioning device by removing the handle and securing the first end of the pulley rope onto itself and over the outer pulley wheel by any means, such as tying a knot or using a karabiner. The second end of the pulley rope is then detached from itself and secured to the handle. It is understood that the pulley apparatus of the present invention may be used by pulling on either end of the pulley rope, using a handle or other device or by pulling on the pulley rope directly. The user may also use both ends of the pulley rope at the same time.

FIGS. 10 through 12 show a pulley apparatus attached to a base support 350 for stand-alone use. The base support consists of two bent tubes welded or otherwise attached to a base plate 345. The base support may include furniture glides 355 or suction cups for even contact with the floor or ground. The base plate 345 is preferably detachable from the pulley apparatus. In one embodiment, the base plate 345 has a collar 357, with a large cut out slot, welded or otherwise attached to the centre of the base plate. The collar 357 has three holes substantially 120° apart, centered in each hole is a plunger barrel welded on the collar, with a threaded knob 359 screwed in each barrel (which is the barrel/knob mechanism described in more detail in FIG. 5). When the pulley apparatus is placed vertically in the collar and all three knobs are tightened, the pulley is secured in the stand and is ready for standalone use. The base support 350 allows the pulley system to be used for on-site training, for example, on sports fields, tennis courts or in gymnasiums without having to be mounted to the ground, wall or any other support. It is understood that the base is of sufficient weight such that the pulley apparatus of the present invention is stable when in use.

FIGS. 13 and 14 show mounting attachments 360 for a pulley apparatus 10 to be mounted to a surface, for example, a wall. Two or more mounting attachments 360 are attached to the housing, by for example, being welded onto the housing, or fastened in any other manner so that they do not significantly move when the pulley apparatus is in use. The mounting apparatus contain bores through which traditional fastening devices may be inserted in order to secure the apparatus to a surface, such as a wall. The mounting attachments 360 may be mounted on the housing such that they do not interfere with the guide rail or guide tube. In an embodiment of the present invention, the mounting attachments are 180 degrees opposite the guide rail. It is understood that the pulley apparatus may be mounted to a surface using any other means so that it is secured to the surface for stable use.

The pulley apparatus of the present invention is adjustable to accommodate different users' heights and body parts.

The pulley apparatus of the present invention may be used for sports training, rehabilitation, warm up and also general physiotherapy for light muscle workouts, for example, patients experiencing scapular retractors injury, rotator cuff injury and knee injury. The pulley apparatus of the invention avoids the ballistic effects of a single axis pulley system. It also provides a wider arc of motion, resistance in a full circle, and superior means to test the range of motion of a particular body part on an individual by the individual doing different exercises or patterns on the pulley apparatus.

The pulley apparatus may be constructed of lightweight materials such as nylon, rope, aluminum housing, and powder coated steel components.

In one example of an embodiment of the present invention the housing may be made of steel or aluminum tube and may have an outside diameter of 1 inch and a wall thickness of 0.123 inches. The top plate and swivel pulley bottom plate may also be constructed of a steel or aluminum plate with a thickness of ¼ inch. All of the pulley wheels are constructed of delrin, aluminum or nylon having an outside diameter of 106 inches and a thickness of 19/32 inches. The swivel pulley bracket 50 is constructed of a steel sheet having a thickness of 0.048 inches. The pulley wheel bracket 200, upper pulley bracket 220 and lower pulley bracket 290 are constructed of a steel sheet and have a thickness of 0.065 inches. The bracket 190 is also constructed of a steel plate having a thickness of 3/16 inches. The weight alignment rods 255 is steel or stainless steel having an outside diameter of 5/16 inches. The upper and lower weight alignment rods 260, 270 are nylon, steel or stainless steel, also having an outside diameter of 5/16 inches.

In this example of an embodiment of the present invention each weight bar is steel or cast iron having an outside diameter of 3.5 inches and a thickness of 1 9/32 inches. The uppermost weight bar 370 is made of steel, aluminum or both. The spacers are nylon and the weight bearing shaft 400 is constructed of aluminum with an outside diameter of 0.75 inches. The top disc plate 410 and bottom disc plate 420 are similarly constructed of aluminum with an outside diameter of 3.75 inches.

The guide rail 120 is constructed of steel or stainless steel and measures 0.75 inches by 0.75 inches with a wall thickness of either 0.125 inches or 0.083 inches. The guide tube 140 is made of steel telespar and measures 1 inches by 1 inches with a wall thickness of 0.105 inches. The plunger barrel 150 and internal supporting cup 160 are constructed of steel round bar, and the plunger barrel has an outside diameter of 0.75 inches and the internal supporting cup has an outside diameter of 0.632 inches. The pulley rope 320 is synthetic or steel wire having an outside diameter of 5.00 millimeters. Both the base and mounting attachments of this example are of steel construction.

The pulley apparatus is lightweight and compact in design allowing for easy transportation with other sports equipment. It is self contained and easy to transport for indoor and outdoor use, for example, at batting cages for injury prevention and warm up purposes.

The pulley apparatus is easy to transport, for use by a clinical practitioner for patient rehabilitation in a clinical setting, as well as a sports trainer for training athletes in sports facilities.

Various embodiments of the present invention having been thus described in detail by way of example, it will be apparent to those skilled in the art that variations and modifications may be made without departing from the invention. The invention includes all such variations and modifications as fall within the scope of the appended claims. 

1. A pulley apparatus for resistance exercises comprising: a housing with an upper end, a lower end, an interior channel extending through the housing, and an exterior surface, a weight stack movable within the housing, and a pulley system comprising in the interior (i) at least two upper pulleys attached to the upper end of the housing, (j) at least one lower pulley attached to the weight stack, and on the exterior surface (k) at least two swivel pulleys attached to the upper end of the housing, (l) first and second outer pulleys, the first outer pulley located below the swivel pulleys and the second outer pulley located below the first outer pulley, and a pulley rope received by the upper pulleys, the lower pulleys, the swivel pulleys and the outer pulleys such that a first end of the pulley rope is secured to one of the outer pulleys and a second end of the pulley rope is received lastly by the other outer pulley, whereby force exerted on the second end of the pulley rope moves the weight stack.
 2. The pulley apparatus of claim 1, wherein the weight stack is comprised of individual weights and additionally includes a weight selection means to adjust the amount of resistance by increments of the individual weights.
 3. The pulley apparatus of claim 2, which additionally includes one or more weight alignment rods in the channel of the housing and holes in the individual weights, whereby the weight alignment rods pass through the holes in the individual weights.
 4. The pulley apparatus of claim 3, which additionally includes a top plate that is secured to the upper end of the housing and a bottom plate that is secured to the lower end of the housing, and wherein the weight alignment rods are secured to the top plate and bottom plate.
 5. The pulley apparatus of claim 4, which additionally includes a guide rail on the exterior surface of the housing and outer pulley positioning devices, wherein the outer pulleys are affixed to the pulley positioning devices, and the pulley positioning devices are capable of being moved along the guide rail or fixed in position on the guide rail.
 6. A pulley apparatus for resistance exercises comprising: an upper housing detachably connected to a lower housing that forms a combined housing with an upper end, a lower end, an interior channel extending through the combined housing, and an exterior surface, a weight stack movable within the housing, and a pulley system comprising in the interior (m) at least two upper pulleys attached to the upper end of the housing, (n) at least one lower pulley attached to the weight stack, and on the exterior surface (o) at least two swivel pulleys attached to the upper end of the housing, (p) first and second outer pulleys, the first outer pulley located below the swivel pulleys and the second outer pulley located below the first outer pulley, and a pulley rope received by the upper pulleys, the lower pulleys, the swivel pulleys and the outer pulleys such that a first end of the pulley rope is secured to one of the outer pulleys and a second end of the pulley rope is received lastly by the other outer pulley, whereby force exerted on the second end of the pulley rope moves the weight stack.
 7. The pulley apparatus of claim 6, wherein the weight stack is comprised of individual weights and additionally includes a weight selection means to adjust the amount of resistance by increments of the individual weights.
 8. The pulley apparatus of claim 7, which additionally includes grooves in the individual weights and one or more weight alignment rods in the upper housing and an equal number of weight alignment rods in the lower housing, whereby in the combined housing, the weight alignment rods are aligned and glide along the grooves in the individual weights.
 9. The pulley apparatus of claim 8, wherein the weight alignment rods in the upper housing are secured to the interior of the upper housing and the weight alignment rods of the lower housing are secured to the interior of the lower housing.
 10. The pulley apparatus of claim 8, which additionally includes a guide rail on the exterior surface of the lower housing and outer pulley positioning devices, wherein the outer pulleys are affixed to the pulley positioning devices, and the pulley positioning devices are capable of being moved along the guide rail or fixed in position on the guide rail.
 11. The pulley apparatus of claims 1 and 6, which additionally includes a base.
 12. The pulley apparatus of claims 1 and 6, which additionally includes mounting attachments on the housing whereby the pulley apparatus may be secured to a surface. 